Toss your tiller for healthier soil, healthier plants and less work in your garden
Conventional garden advice usually involves adding a lot of amendments to your soil every year and tilling it in to mix it thoroughly. The idea is to add new organic matter that will add nutrients and structure to the soil, aerate the soil, and make you soil fluffy so it will drain well. We have all done this. We did it for years in our garden with the same results every year. Our vegetable struggled. Halfway through the growing season, our soil was hard as rocks and water just ran off the top. Ever wonder why that happens? Do you, like I did, wonder what you had done wrong in preparing your beds?
What you are doing wrong, just like I was doing wrong, was accepting that conventional advice was correct when, in fact, it is wrong on so many levels it is shocking.
Understanding Soil Structure
We need to understand how soil structure and biology work. It is a complex subject, but I think I can simplify it down enough to get the basics across. Soil is a living ecology. It is not just a support structure for plant roots and a place where nutrients sit and wait for plant roots to find them. Life in healthy soil is more plentiful than anywhere else on earth. Healthy soil teams with everything from microscopic life to earthworms and other small creatures that all work together to create healthy, vibrant biology.
In healthy soil, a network exists of bacteria, fungi, and small organisms like earthworms that breakdown larger organic particles into their constituent parts. This breakdown is decomposition and everything organic decomposes. It is the constituent parts of this decomposition that plants need to be healthy as well. We call them nutrients.
But how do these nutrients get to the plant? Most gardeners assume that the plant roots reach out into the soil, grab those nutrients, and then deliver them up to the leaves where photosynthesis occurs where the plants use the transported nutrients to build leaves, stems and fruit. This assumption is partially true.
Plant root systems are limited in their scope. Most plant root systems are not as big or as extensive as you would think. Extending this system is where that microbiome in the soil comes into play. In healthy soil, bacteria will flourish, and a network of fungi will grow. This fungus is called mycorrhizae and it is this fungus that is the key to the whole system. It does so much that without a healthy mycorrhizae network, it is almost impossible to have healthy soil.
The Fungus Key
First, the mycorrhizae fungi spread far beyond the area that plant roots can reach. The fungi network transports nutrients and water back to the plant roots where, in a symbiotic relationship, the fungi network trades water and nutrients for sugars produced by the plant.
Second, the mycorrhizae act as a go-between with the bacteria in the soil and the plant. Plants need different amounts and types of nutrients during different parts of the growth cycle. Plants exude enzymes with the sugars that they trade to the fungi. These enzymes differ depending on what the plant’s needs and the fungi and bacteria respond by producing more of the needed nutrients.
The third major contribution that the fungi web brings to the soil is its exudates. Mycorrhizae exude a substance called glomalin. This substance acts to bind the various constituent parts of the soil into larger particles called aggregates. The soil has three components, sand, silt, and clay. The ration of each determines the type of soil have. Unless these particles are aggregated, your soil will compact become rocklike and resist water infiltration. It also makes it much harder for plant roots to build their structure and almost impossible for small creatures and bacteria to survive in the soil. The exudates from the bacteria and the fungi act like glue to hold these particles together in much larger chunks. Aggregation creates a soil structure that is rich in holes and voids, which facilitates water infiltration and air exchange in the soil. The pores created in the soil are where the bacteria thrive and where the small microscopic hair-like structures of the fungi network exist.
Now we understand why your soil starts to turn to rock as soon as you water it the first time. In soil that is not aggregated, water settles the much smaller sand, silt, and clay particles together into a tight matrix where they wedge together and become a solid mass.
Toss your Tiller for better Soil Health
Preventing this compaction is the main reason we advocate a no-till approach to gardening. Each time you till the soil, you are destroying the majority of that fungi and bacteria network in the soil. You break up those aggregates and the first time you water or it rains, the soil starts to compact, which further inhibits the regrowth of the fungi and bacteria and the problem grows.
The answer is simple. Toss the tiller and start building soil naturally. No one goes into a forest and tills up the soil to keep it rich and vibrant. No one tilled the prairie, which was one of the richest biomes that we have ever found.
We should try to mimic those processes and that includes a no-till approach in the garden. We want to encourage fungi and bacteria growth in several ways.
Don’t Disturb the Soil
No-Till! Let that biome in your soil alone. Let it do its job. Tilling not only destroys much of the microbiome, but it also encourages weed growth and disease.
Feed the Soil, Not the plants.
Healthy soil will deliver everything your plants need, in the right proportions at the right time, thanks to the interaction of the fungi network, the bacteria in the healthy soil, and your plant roots. The best thing you can do for your soil and the biome that exists there is to routinely add high-quality organic compost to the top of the soil. The best way to add this organic matter is in the form of compost from your compost bin or compost tea applied as a drench.
Keep your soil mulched. The mulch can be wood chips, straw, green compost, or living compost. The idea is not to have bare soil exposed. Bare soil exposed to the sunlight is soon devoid of bacteria and fungi. The UV rays in sunlight act as a sterilant and turn the top few inches of soil into a dead zone. Nature itself abhors bare soil and uses weeds to cover it. Most weeds germinate well in soil that is bare and exposed but doesn’t germinate well where some kind of mulch is present. Good organic mulch decomposes and is continually adding organic nutrients to the soil. It helps the soil retain water and moderates soil temperature.
Water slowly and deeply.
Water so that the moisture has time to infiltrate deeply into the soil. Remember those channels in your aggregated soil are small. Slow watering allows time for the moisture to penetrate deeply into your soil where it is less likely to evaporate and disappear.
Toss your Tiller.
With a few exceptions, your tiller should be one of your least used garden tools. A small tiller is handy at times when you are building or establishing new beds. Use it to mix your soil amendments. Building new beds is about the only time we advocate using a tiller in your garden.
Remember that the goal is to build a healthy soil biome and then not disturb it but allow it to continue to flourish and do its work. A healthy soil and soil biome will take care of the plant and is true of vegetables, ornamentals, annuals, perennials and woody plants such as shrubs and trees. So, toss your tiller.